Electrically heated mattress and sleeping pad



' g- 1955 H. c. ABBOTT ET AL ELECTRICALLY HEATED MATTRESS AND SLEEPINGPAD Filed March 12, 1955' 3 j yyfoiidf gi/milai ZZ 00mm g 97mm v 5% W 10fir? United States Patent ELECTRICALLY HEATED MATTRESS AND SLEEPING PADHoward C. Abbott, Chicago, and Thomas J. McDermott,

- Oak Park, Ill.

Application March 12, 1953', Serial No. 341,858

3 Claims. (Cl. 21946) Our invention relates to an electrically heatedmattress and sleeping pad.

One of the objects of this invention is to provide an electricallyheated mattress and sleeping pad, formed of a foam latex material of athickness which will cause the heat to be transmitted to the body andwhich will cushion the heating element so that same does not impart anyunevenness or lumping to the pad.

Other objects of this invention are to provide an electrically heatedmattress and pad formed of a material such as foam latex which may beused by persons with allergic conditions, which will not absorb liquids,moisture or perspiration, which is sanitary, and which is highlyresilient.

The prior art electrically heated mattress and sleeping pads are made ofa cloth or fabric material in which the heating element is sewn orstitched to the cloth. Such cloth pads or coverings are objectionable topersons suffering from allergic conditions, likewise the cloth tends toabsorb water, moisture and perspiration and hence become unsanitaryunless cleaned frequently. Furthermore such cloth coverings are notsufficiently resilient. In addition such fabric coverings require theuse of sewing machines and skilled operators and the stitching of theheating element or electric wire to the pad is laborious and timeconsuming, all adding to the cost of the product. All of the foregoingobjections are eliminated with the use of this invention.

Other objects will become apparent at this description progresses:

In the drawing:

Fig. 1 is a top plan view partly broken away of a heated mattress andsleeping pad in accordance with our invention.

Fig. 2 is an enlarged cross-sectional view taken on lines 22 of Fig. 1,and

Fig. 3 is a cross-sectional view taken on lines 33 of Fig. 1.

The pad is made up of a pair of layers of foam latex material, indicatedat and 12, cemented together, between which is secured, as will bepresently described, the heating means. The layers 10 and 12 of foamlatex material are each approximately inch in thickness and of a lengthand width of the size of a mattress.

The heating means generally indicated at 14, which is positioned betweenthe two layers 10 and 12, comprises a resistant alloy wire 16 preferablyof a size number 33, American Wire Guage. This wire is wound helicallyaround a plastic core 18 and both the core 18 and wire 16 are enclosedin a sleeve 19 which is formed of a thermoplastic coating compound. Thewire 16 preferably has a resistance of three ohms per running foot anddevelops a maximum temperature of 75 C. The heat developed by the pad isdetermined by the total resistance of the heating means, the length ofwhich is adjusted so as to develop a temperature which is about threedegrees above normal body temperature. This condition is true so long asthe heat can be dissipated into the surrounding space. Thus, under sucha condition the heat of the pad will never exceed the temperatureindicated. The heating means 14 is preferably in a continuous length, asshown in Fig. 1, and is arranged in a pattern comprising a series ofreversing lines which are spaced in substantially parallel relationshipso as to cover approximately of the area of the pad. Thus, the headportion of the pad indicated by the numeral 17 upon which the pillowrests has no heating means, while the major portion of the pad on whichan individual would normally recline, is substantially covered with anetwork of the heating means. While the heating means is shown asarranged in a reversing line pattern, it will be understood that it maybe arranged in any suitable pattern, such as concentric circles, aspiral or any other pattern desired.

A rubber cement 20 is applied to the inside of each of the layers 10 and12 and the heating means is then laid out, as shown in Fig. 1 on one ofsaid layers and the other layer is then superimposed so that the twolayers of foam latex adhere to each other with the heating elementsecurely positioned therebetween.

The terminal portions 14a and 14b of the heating means 14 are attachedto the terminals of a conventional electric cord 22 which is connectedto a conventional elec tric plug 24. A switch 26 may be connected on thecircuit. A strip of tape material 28 of rectangular shape is positionedadjacent the electrical cord 22 and is cemented and secured between thetwo layers of foam latex 10 and 12. This prevents any breaking ordisconnecting of the terminal portion which may be caused normally byvirtue of any tensile stresses applied to the cord.

With the two layers secured as described, a fabric tape 30 is rubbercemented and secured to the border completely around the sides and endsof the pad with the fabric tape overlapping the layers. The pad may becleaned in the usual manner in which foam latex is cleaned. Theelectrical wires associated therewith are completely enclosed andwaterproofed. Since foam latex is an insulator, uncovered electricalwire may be used. The pad may be used for infants as it will not absorbany liquid, nor will it absorb moisture or perspiration. Due to theresiliency of the pad the danger of breaking of the electrical wire 16is eliminated.

In use, the pad aforedescribed is merely placed on a conventionalmattress to overlie the top surface thereof.

It will be understood that various changes and modifications may be madefrom the foregoing without departing from the spirit and scope of theappended claims.

We claim:

1. An electrically heated mattress pad adapted to be removablypositioned over a mattress and comprising a pad body formed of a pair offoam latex layers secured together by a rubber cement, each layer beingapproximately A inch in thickness and of a size to substantially coveran entire mattress, an electrical heating element disposed and securedbetween said layers to cover substantially not more than three-fourthsof the area thereof with the head portion of said pad without saidheating element, said heating element adapted to develope a maximumtemperature of C. and including a wire spirally wound around a core withsaid wire and core covered by a sleeve in contact with the adjacentsurfaces of said latex layers, and a tape secured around the border ofsaid pad.

2. An electrically heated mattress pad adapted to be removablypositioned over a mattress and comprising a pad body formed of a pair offoam latex layers secured together by a rubber cement, each layer beingapproximately A inch in thickness and of a size to substantially coveran entire mattress, an electrical heating element disposed and securedbetween said layers to cover substantially not more than three-fourthsof the area thereof with the head portion of said pad without saidheating element, the terminal portions of said heating element connectedto an electrical cord extending through said head portion adjacent oneside thereof, a strip of tape material positioned adjacent theelectrical cord and cemented and secured between the foam latex layers,said heating element adapted to develope a maximum temperature of 75 C.,and a tape secured around the border of said pad.

3. An electrically heated mattress pad adapted to be removablypositioned over a mattress and comprising a pad body formed of a pair offoam latex layers secured together by a rubber cement, each layer beingapproximately inch in thickness and of a size to substantially cover anentire mattress, an electrical heating element disposed and securedbetween said layers to cover substantially not more than three-fourthsof the area thereof With the head portion of said pad without saidheating element, the terminal portions of said heating element connectedto an electrical cord extending through said head portion adjacent oneside thereof, a strip of References Cited in the file of this patentUNITED STATES PATENTS Re. 21,474 McCleary June 4, 1940 1,837,117 DunbarDec. 15, 1931 1,997,899 Dick Apr. 16, 1935 2,288,232 Driscoll June 30,1942 2,298,181 Stranszky Oct. 6, 1942 2,606,996 Westerberg et al. Aug.12, 1952 2,688,070 Freedlander Aug. 31, 1954

